Magnetically actuated proximity switches have been used to sense the relative movement between two member, one carrying the switch and the other being a magnetically permeable member, usually iron or steel. A major problem in the design of magnetically actuated proximity switches is to get adequate pressure between the electrical contacts of the device at reasonable sensing distances. This invention relates to an improvement in a magnetically actuated switch such as that shown in FIG. 5 of U.S. Pat. No. 3,176,096, issued to Charles R. Marcum. Specifically the control member or armature is improved to increase the sensitivity and the contact pressure between the contacts of the device in response to a given diversion of flux from the armature of the device.
In a proximity switch according to the invention the control member or armature, which carries the movable contacts, is provided at its ends with magnetically permeable lips extending toward the marginal area of the pole faces of the permanent magnets with which the armature cooperates.
A preferred form of the invention is illustrated in the accompanying drawings.